Automotive seat

Abstract

An automotive or similar type vehicle seat comprising a seat back having an adjustable central portion which may be selectively adjustably positioned to minimize driver fatigue. The adjustable area is actuatable upon rotation of an adjustment knob which controls rotation of a shaft which is connected via suitable linkages to a pivotal support mechanism for pivotably adjusting the central portion of the seat back.

I claim: 
     
       1. In a vehicle seat of the type having a seat portion, a seat back portion including a bolster frame, and a moveable lumbar support pad in the seat back portion, an improved lumbar support assembly comprising: a support frame pivotable about a generally horizontal axis about the lower portion of said support frame,   a threaded axle mounted for rotation to the bolster frame extending along a generally horizontal axis,   at least one thread holder engaging said threaded axle,   at least one joint rod having a first and second end, said first end pivotably fixed to said thread holder,   a second axle pivotably attached to said joint rod second end, said second axle engaging at least one elongated slot formed by the bolster frame,   at least one joint lever having a first and second end, said first end pivotably attached to said second axle, said second end pivotably attached to said support frame whereby rotation of said threaded axle causes said thread holder to move along said threaded axle thus causing   the position of said second axle within said slot to change thereby causing said joint levers to effect changes in the position of said support frame.   
     
     
       2. The vehicle seat according to claim 1 wherein a pair of said thread holders are pivotably fixed to a pair of said joint rods. 
     
     
       3. The vehicle seat according to claim 2 wherein a pair of said joint levers are pivotably attached to both said second axle and said support frame. 
     
     
       4. The vehicle seat according to claim 2 wherein said threaded axle includes first and second threaded portions, said portions having opposing thread direction such that upon rotation of said threaded axle, said thread holders move either toward or away from one another along said threaded axle. 
     
     
       5. The vehicle seat according to claim 1 wherein a pair of said slots are formed by said bolster frame. 
     
     
       6. The vehicle seat according to claim 5 wherein said slots extend in a substantially vertical direction.